Flywheel magneto



SBpt' 10, 1957 R. E. PHELON 2,806,156

FLYWHEEL MAGNETO /NVENTO RUSSELL E. PHE/ ON A TTOPNEV Sept. 10, 1957 R E;- PHELON 2,806,156

FLYWHEEL MAGNET() Filed Nov. 5. 1954 2 Sheets-Sheet 2 /N VE N TOR RUSSELL EPHEL ON A T TOR/VEV United States Patent O FLYWHEEL MAGNE'ro Russell E. Phelon, Longmeadow, Mass. Application November s, 1954, serial No. 467,149 14 Claims. (Cl. 31o- 70) This invention relates to a high tension magneto and, more specifically, to an improved flywheel type magneto for use with an internal combustion engine.

As used herein, the term flywheel type is meant to refer to magneto constructions which comprise a rotor or ywheel adjacent or surrounding a nonrotatable or stator structure including the magneto coil and core.

It is common practice on small engines which are started with a rope or a kick starter to set the spark so that it occurs in the neighborhood of, for example, 30 before top dead center of the piston. It is possible tov crank the engine over fast enough so that the piston will not reverse itself and kick Even if it does kick the operator Will not be injured because of the nature of the starting mechanism.

For a relatively large engine that is to be cranked by hand it is dangerous to have the spark advanced to an extent even approximating 30 during starting, although this degree of advance may be necessary for normal engine operation. It has heretofore been proposed to make the breaker operating cam adjustable relatively to its shaft so that there is little or no spark advance when the engine is at very low speed, as for instance during starting, and so that the required spark advance is attained as the engine reaches normal operating speed. The cam for yoperating the breaker mechanism may be automatically adjusted by a speed responsive mechanism so as to be advanced as the speed increases and so as to be retarded as the speed decreases.

Flywheel magnetos are ordinarily designed to operate satisfactorily with only one relationship between the rotor and the stator thereof, no substantial variation from this relationship being possible. The general object of the present invention is to provide a ywheel magneto wherein the relationship between the rotor and the stator may be widely varied, that is, throughout 30 or more, and wherein a satisfactory spark is always obtained notwithstanding the varying relationship.

Other objects of the invention are to provide various structural features which contribute to the attainment off the above-stated more general object.

In the drawings i have shown in detail a preferred'. embodiment of the invention, but it will be understood. that various changes may be made from the construction shown, and that the drawings are not to be construed as. defining -or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Of the drawings:

Fig. 1 is a vertical transverse sectional view of a magneto embodying the invention, the section being taken. along the line 1 1 yof Fig. 2.

Fig. 2 is a vertical longitudinal sectional View taken along the line 2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 but showing the breaker cam in a subsequent position for separating the breaker' points and showing the other movabie parts in corre-l sponding positions.

2,806,156 Patented Sept. 10, 1957 r'ce Fig. 4 is a View similar to Figs. 1 and 3, but showing the breaker cam in a retarded position with respect to other rotatable parts, the breaker cam being in the same position as in Fig. 3 but the other rotatable parts being in positions beyond those shown in Fig. 3.

Fig. 5 is a View similar to Figs. 1, 3 and 4, but showing the breaker cam in a more retarded position with respect to other rotatable parts, the breaker cam being in the same position as in Figs. 3 and 4 but the other rotatable parts being in positions beyond those shown in Fig. 4.

Fig. 6 is a diagram of electrical connections.

As shown in the drawing, the stator or core structure of the magneto is carried by a suitably supported nonmagnetic frame 10. The frame 10 is shown as having a central opening through which extends a shaft 12 rotatable in suitable bearings, not shown. The shaft 12 may be an extension of the crankshaft of the engine with which the magneto is to be used or it may be an entirely separate shaft, but in any event it is rotated in timed relationship with the engine.

The core structure comprises a magnetic core which is preferably laminated as shown in Fig, 2 and which is formed and arranged to provide a plurality of circularly spaced poles having circularly extending faces 14, 16 and 18. The said core faces are in a surface of revolution, preferably a cylindrical surface, concentric with the axis of the shaft 12 and they are equidistant from the axis. Preferably and as shown, the core faces are respectively on circularly extending core projections 20, 22 and 24. The projections 20 and 24 with their faces are opposite each other and they are connected by a central core portion 26. The projection 22 has two oppositely projecting portions which cooperate with a central vertical stem 23 to provide a T-shape. Said projection 22 with its face 16 is preferably midway between the projections 20 and 24 and is carried by a central vertical stem 2S which engages the central core portion 26.

Primary and secondary generating coils 30 and 32 surround the central stem 28. The coils 30 and 32 preferably constitute a coil unit which is formed separately from the core, as it is not ordinarily practicable to wind the coils in place. When the coils are a separate unit, the core is formed with the portions 26 and 2S constituting separate first and second core pieces with a joint between them. The central connecting portion of the V`first core piece 26 and the central stern of the second core piece 28 are separable so as to permit assembly of the coil unit with the core. After being formed, the coil unit can be placed on the stem and then the two pieces of the `core may be assembled. The stem of the second pole piece 28 is -preferably notched as shown to provide two downward projections 34, 34 having oppositely inclined inner or beveled faces and two substantially parallel outer faces. The central portion 26 of the lower or first core piece is notched to receive and fit the projections 34, 34, said notch having faces which the beveled and parallel faces engage and fit. After the coil unit is in place as shown and after the two core pieces have been assembied, :the said parts are held in their proper relationship by Iscrews 36 and 38, 3S which connect them to the frame 10. The inclined or beveled faces at the joint between the two core pieces provide a relatively large area for the .transfer of magnetic iiux from one part of the core to the 'other part thereof.

The primary coil 30 has a relatively smail number of .j

grounded end of the primary coil is connected by means of an insulated conductor 40 with breaker points 42 and 44. The point 44 is grounded and the point 42 is carried by a rocker arm 46 pivoted at 4S to the frame 10. The rocker arm 46 has an extensionSG which is engaged by a cam 52 mounted on the shaft 12 for rotation therewith. A spring S4 serves to bias the arm 46 to move the point 42 into engagement with the point 44, and this spring, or an auxiliary conductorassociated therewith, serves to provide an electrical connection between the conductor 49 and the said point 42. When the shaft 12 is rotated the cam S2 oscillates the rocker arm 46 to make and break the electrical connection between the points 42 and 44. The cam 52 is shown as having its major portion cylindrical for holding the breaker point 42 separated from the breaker point 44. The cam, as shown, has a substantially fiat portion which upon engagement 'with the rocker arm extension Sil first permits engagement of the points to close the circuit and then separates the points to interrupt the circuit. Alternatively, the cam 52, instead of having the disclosed extensive cylindrical portion, may have a single short lobe which serves to only momentarily Vopen the circuit. A condenser 56 is connected in parallel with the breaker points 42 and 44 in accordance with customary practice.

The secondary coil 32 is suitably grounded, for instance by being connected with the same screw 38 which is used for grounding the primary coil. The secondary coil is provided at its ungrounded end with an insulated conductor S8 which extends to the spark plug of the engine.

The magneto as hereindisclosed, more particularly as to the rotatable field structure thereof, embodies the invention set forth and claimed in my Patent No. 2,472,313, dated J une 7, 1949, for Flywheel Magneto. The magneto, as to the rotatable field structure thereof, preferably further embodies the invention set forth and claimed in my Patent 2,538,534 dated January 16, 1951 for Rotor for Flywheel Magneto and Magnet Unit Therefor. The present invention is not, however, necessarily limited to the use of the inventions disclosed in the said patents.

The rotatable field structure includes a flywheel 60` which is carried by the shaft 12, being held in place by a nut 62 and being rotatably connected by a key. The flywheel includes a peripheral annular flange 64 which preferably surrounds the core structure, and the flywheel or at least the said flange thereof is formed of magnetic metal.

In accordance with the invention the flange 64 of the flywheel 60 carries a plurality of permanent magnets having their outer faces connected with the magnetic connecting means of the flywheel and having their inner faces movable in close proximity to the pole faces 14, 16 and 18. Some of the magnets are charged in one direction and some in the opposite direction. Preferably there are two groups of Vpermanent magnets, the magnets of one group having the same polarity and being charged in VoneV direction and the magnets of the other group having the opposite polarity and being charged in the opposite direction. When the flywheel flange 64 surrounds the core structure, the magnets of said groups extend radially inwardly from the flange and they are charged radially. As shown, there are two magnets or a pair of magnets in each group, but each group may have a larger number of magnets. The magnets of one group or pair are designated 66 and 68 and they have their North orV positive poles toward the center and the magnets of the other group or pair are designated 70 and 72 and they have their South or negative poles toward the center.

The magnets may be variously connected to the flywheel flange, but preferably they are connected as shown in my said Patent 2,538,534. A portion of the internal face 74 of the flywheel flange 64 conforms to Va cylinder, and a circularly extending connecting deviceis provided which has its external face in engagement with the internal face 74 of the flywheel flange. The outer faces of the several magnets 66, 68, 70 and 72 directly engage and are connected to the internal face of the connecting device. For convenience of manufacture and assembly the connecting device comprises two similar separate circularly extending connecting members 76 and 78 having a narrow space between them. The magnets 66 and 68 are connected to the member 76 and the magnets 70 and 72 are connected to the member 78. Screws are provided for connecting the connecting means or connecting members to the iiange of the iiywheel. When there are two separate connecting members, three screws are preferably provided for each of them, the member 76 being held by screws 80, 80 and the member 78 being held by screws 82, 82.

The magnets 66, 68, 70 and 72 are provided respectively at their inner faces with circularly extending arcuate pole pieces 84, 86, 88 and 90. The several parts are so proportioned and related that the arcuate inner faces of the pole pieces are concentric with the axis of rotation and are movable in close proximity to the arcuate outer faces 14, 16 and 18 of the core. The several magnets are preferably connected to the connecting device or connecting members by brazing or soldering and the several pole pieces are similarly connected to their respective magnets.

For convenience of description the term magnets is hereinafter sometimes used to refer collectively to the magnets proper and to their respective pole pieces. Also, for convenience of description the connecting members 76 and 78 are sometimes hereinafter referred to collectively as a magnetic connecting device.

For counterbalancing the magnets and the connecting members and the pole pieces, the flywheel is provided with a counterweight 92. This is preferably formed integrally with the flange 64 of the flywheel.

The two magnets 66 and 68 of one group with their pole pieces 84 and 86 are substantially spaced circularly and the two magnets 70 and 72 of the other group with their pole pieces 8 and 90 are similarly spaced. A wider spacing is provided between the adjacent magnets 68 and 70 of the two groups and their pole pieces 86 and 88. The two groups or pairs of magnets are so related to each other and to the pole faces of the core and to the cam 52 that the several parts in one position of rotation are in the positions shown in Fig. l. The magnet pole pieces 84 and 86, except for the small space between them, extend throughout the length of the core pole face 14 and somewhat beyond the ends of the said pole face. Similarly, the magnet pole pieces 88 and 96, except for the small space between them, extend through the length of the core pole face 16 and somewhat beyond the ends of the said pole face. Rotation is in the clockwise direction and the cam 52 is in position to permit the movable breaker point 42 to be moved by the action of the spring 54 for closing the circuit.

Before the parts reach the position shown in Fig. l, the leading positive magnet 68 of the first group and the leading negative magnet 72 of the second group start to register respectively with the first and second core faces v14 and 16 and a counterclockwise magnetic circuit is established from the positive magnet 68 through the central core portions 26 and 28 and through the negative magnet 72. The magnetic circuit is completed from the magnet 72 through the connecting member 7S, through the fly-wheel flange 64 and through the connecting member 76 to the magnet 68. This counterclockwise magnetic circuit is indicated by the arrows a, a and it extends through the core stem 28 and thus through the primary and secondary coils 30 and 32.

The magnetic ux in the last above-described circuit is increased as the magnets 68 and 72 come fully into register with said pole faces and is additionally increased as the magnets 66 and 70 also come into register with said pole faces. There is therefore a progressive increase in the amount of flux through the stem 23 and through the coils through a relatively wide rotative angle until a maximum is reached with the parts in the Figyl position.

When the parts have advanced to the position shown in Fig. 3, the trailing positive magnet 66 is still in partial register with the core face 14 and the trailing negative magnet 7i) is still in partial register with the core face 16. However, the leading positive magnet 68 has moved into partial register with the core face 16 and the leading negative magnet 72 has moved into partial register with the core face 18. The magnets 66 and 72 now establish a magnetic shunt circuit in the clockwise direction through the connecting portion 26 of the core and through the flywheel flange 64 as indicated by the arrows b, b. At the same time the magnets 63 and 70 establish a magnetic shunt circuit in the counterclockwise direction through the outer projecting portion 22 of the core and through .the ywheel flange 64 as indicated by the arrows c, c. Neither of the said shunt circuits extends through lthe stem 28 or the core or through the coils.l j

As the magnets move to the Fig. 3 positions, there is a sudden reduction or collapse ofthe flux in the magnetic circuit through the stem 28 and through the coils. The vcam 52 is so located as to cause the separation or" the breaker points 42 and 44 during the period of flux reduction or collapse, that is, immediately before the magnets reach the positions shown in Fig. 3. The separation of the points interrupts the circuit in the primary coil and generates high voltage in the secondary coil. This action will be more readily apparent from the electrical diagram in Fig. 6, wherein it should be understood that the breaker point 42 has just been separated from the breaker point 44 to interrupt the circuit through the primary coil 30. The spark plug is indicated at 94 and is in series with the secondary coil so that a spark is caused by the high voltage in the said coil.

immediately upon movement of the parts beyond the Fig. 3 position, the positive magnet 68 starts to prevail over the negative magnet 7i? and the negative magnet 72 starts to prevail over the positive magnet 66 with the result that the fluxes in the described shunt circuits are rapidly reduced. At the same time the leading positive magnet 68 and the leading negative magnet 72 by reason of their partial registration with the pole faces 16 and 18 start to establish a reversed magnet circuit through the core stern 28 and the coils as more fully explained in connection with Fig. 4.

As shown in Fig. 4, the rotor parts are advanced beyond the positions shown in Fig. 3, and in said Fig. 4 positions the trailing positive magnet 66 is out of register with the pole face Efiand the leading positive magnet 68 is fully in register with the pole face 16. The trailing negative magnet 't is out of register with the pole face t6 and the leading positive magnet '72 is fully in register with the pole face i3. Thus the magnets 66 and 70 are ineffective but the magnets 68 and '72 have acted to build up a magnetic circuit in the counterclockwise direction through the core portions 28 and 26 and through the flywheel flange 64 as indicated by the arrows d, d. The last said circuit extends in the reverse direction through the core stem 2S and through the coils.

As shown in Fig. 5, the various rotor parts are additionally advanced. Both of the positive magnets 66 and 63 are in register with the pole face 16 and both of the negative magnets 7@ and 72 are in register with the pole face 18. Thus the four magnets cooperate to establish a magnetic circuit similar to that described in connection with Fig. 4 and indicated by the arrows e, e, but having a greater magnetic flux for the reason that the circuit results from the action o-f four magnets instead of only two magnets.

There is therefore a progressive increase in the amount of ilux through the stem 28 from the Fig. 3 position to the Fig. 5 position, this increase being due to the progressive registration of magnets in the two groups with the second and third pole faces 16 and 18. This makes it possible to generate a satisfactory spark throughout a 6 wide angle of rotation as represented for instance by the rotation from the Fig. 3 position to the Fig. 5 position.

As previously pointed out, the breaker cam 52 may be connected with the shaft 12 so as to be advanced or retarded, preferably automatically, as the engine speed increases `0r decreases. The mechanism `for adjusting the cam 52 does not of itself constitute a part of the present invention, but the cam is shown as being on a sleeve 96 which normally rotates in unison with the shaft 12 but which is rotatably adjustable with respect to the said shaft. Rotative adjustment of the sleeve relatively to the shaft serves to advance or retard the cam 52 andv therefore to advance or retard thetiming of the spark. The sleeve 96 and the adjusting mechanism therefor 'constitute means enabling the breaker mechanism to be adjusted to change the timing of the separation of the breaker points. The amount of ux increases from the Fig'. 3 position to the Fig. 5 position, and the cam 52 can be adjusted for breaking the circuit at said positions or anywhere between them.

Fig. 4 shows the cam 52 relatively retarded so that it is in the same position as in Fig. 3 notwithstanding the more advanced positions of the rotor parts. Similarly, Fig. 5 shows the cam 52 relatively retarded additionally sothat it is in the same position as in Figs. 3 and 4 notwithstanding the still more advanced positions of the rotor parts.

As the parts move to the Fig. 4 position and then to the Fig. 5 position, there is a progressive rapid increase in the ux through the stem 28 and through the coils. In each position the cam 52 serves to cause the separation of the breaker lpoints during the period of fiux increase, thus interruptingv the circuit in the primary coil and generating high voltage in the secondary coil. This occurs at any cam adjustment within a relative wide range and said high voltage causes a spark at the spark plug 974.r j

From the foregoing description of the manner of operation as illustrated particularly in Figs. 3, 4 and 5, it will be seen that conditions are maintainedfor the generation of a suitable spark at the spark plug 94 notwithstanding a considerable variation in the relative position of the cam.

The relative positions of the cam 52 in Figs. 4 and 5 have been described as retarded with respect to the relative position in Figs. 1 and 3. It follows that the relative positions of the cam in Figs. 4 and 3 are advanced with respect to the position in Fig. 5. The position of the cam in Fig. 5 is the most retarded position, and this is the position for manual starting, ignition taking place at or near the dead center position of the engine. After starting yand as the motor speed approaches normal, the cam 52 is advanced to correspondingly advance the spark to whatever extent is found best for satisfactory motor operation. Ordinarily advance of the cam 52 to the position shown in Fig. 4 is suicient for normal operation of the engine. However, the cam may be further advanced to the position shown in Fig. 3. The cam and the spark are automatically advanced or retarded as the engine speed increases or decreases. The design of the magneto as hereinbefore described is such that there is suitable spark generation notwithstanding the advance of the spark over a substantial range and beyond the extent ordinarily regarded as desirable.

The described T-shape of the core pole carrying the coils is an important feature of the invention. This permits effective action of the two pairs of magnets as described, and it increases the area for the transfer of ux through the air gap, which in effect reduces the reluctance of the gap.

The invention claimed is:

1. In a flywheel magneto, the combination of a rotatable shaft; a stationary Core structure adjacent the shaft including circularly spaced first and second and third poles magnetically connected at their inner ends and having outer faces in a surface of revolutionand extending circularly to substantial extents which second pole includes a stem, the core structure also including a primary coil surrounding the stem of the second pole and spaced inwardly from the face of said pole; a ywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; two groups of permanent magnets carried by the iiywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, the magnets of one group being charged in one direction and the magnets of the other group being charged in the opposite direction and the magnets of the two groups being so spaced and related that during each rotation the leading magnets of the two groups move approximately simultaneously into register respectively with the faces of the second and third poles to initially establish a magnetic circuit through said second and third poles and through the coils, the flux in the said circuit being progressively increased to a maximum as other magnets of said groups move into register respectively with said faces of said second and third poles; and a breaker mechanism including separable points in series with the primary coil and including means for causing the repetitive separation of the points in timed relationship with the movement of the magnets into register as stated with said second and third poles.

2. A flywheel magneto as set forth in claim 1, including means enabling the breaker mechanism to be adjusted so that the separation of the breaker points during each rotation of the ywheel and magnets may take place at any time during the progressive increase in the ux in said circuit.

3. In a flywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including circularly spaced rst and second and third poles magnetically connected at their inner ends and having outer faces in a surface of revolution and extending circularly to substantial extents which second pole includes a stem and has its face substantially equally spaced from the faces of the rst and third poles, the core structure also including primary and secondary coils surrounding the stem of the second pole and spaced inwardly from the face of said pole; a flywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; two groups of permanent magnets carried by the flywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, the magnets of one group being charged in one direction and the magnets of the other group being charged in the opposite direction and the magnets of the two groups being so spaced and related that during each'rotation the leadingrmagnets of the two groups move approximately simultaneously into register respectively with the faces of the second and third poles to initiallyrestablish a magnetic circuit through said second and third poles and through the coils, the flux in the said circuit being progressively increased to a maximum as other magnets of said groups move into register respectively with said faces of said second and third poles; and a breaker mechanism including separable points in series with the primary coil and including means for causing the repetitive separation of the points in timed Vrelationship with the movement of the magnets into register as stated with said second and third poles.

4, VA ywheelmagneto as set forth in claim 3, including means enabling the breaker mechanism to, be adjusted so that the separation of the breaker points during each rotation of the flywheel and magnets may take place at any time duringthe progressive increase in the flux in said circuit. e v

.5. Ina flywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including circularly spaced first and second and third poles magnetically connected at their inner ends and having outer faces in a surface of revolution and extending circularly to substantial extents which second pole includes a stem, the core structure also including a primary coil surrounding the stem of the second pole and spaced inwardly from the face of said pole; a liywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; two groups of permanent magnets carried by the flywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, the magnets of one group being charged in one direction and the magnets ofthe other group being charged in the opposite direction and the magnets of the two groups being so spaced and related that during each rotation they establish a magnetic circuit through the rst and second poles and through the coils and that in a subsequent position during each rotation they simultaneously establish'two shunt magnetic circuits one extending through the second pole near the outer face thereof and independently of the stem thereof and the other extending through the first and third poles independently of the second pole; and a breaker mechanism including separable points in series with the primary coil and including means for causing the repetitive separation of the points in timed relationship with the establishing of said shunt magnetic circuits.

6. A iiywheel magneto as set forth in claim 5, wherein the second pole of the core structure has its face substantially equally spaced from the faces of the first and third poles, and wherein there is aiso a secondary coil surrounding the stem of the second pole and spaced inwardly from the face of said pole. Y

7. In a flywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including circularly spaced rst and second and third poles magnetically connected at their inner ends and having outer faces in a surface of revolution and extending circularly to substantial extents which second pole includes a stem, the core structure also including a primary coil surrounding the stem of the second pole and spaced inwardly from the face of said pole; a iiywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; two groups of permanent magnets carried by the flywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, the magnets of one group being charged in one direction and the magnets of the other group being charged in the opposite direction and the magnets of the two groups being so spaced and related that during each rotation they establish a magnetic circuit through the first and second poles and through the coils and that in a subsequent position during each rotation they simultaneously establish two shunt magnetic circuits one extending through the second pole near the outer face thereof and independently of the stem thereof and the other extending through the first and third poles independently of the second pole and that in a further subsequent position during each rotation they establish a magnetic circuit through the second and third poles and through the coils in a direction opposite to that of the Vfirst said circuit; and a breaker mechanism including separable points in series with the primary coil and including means for causing the repetitive separation of the points in timed relationship with the rotation of the flywheel and magnets.

8. A flywheel magneto asset forth in claim 7, wherein the second pole of the core structure has its face substantially equally spaced from the faces of the first and third poles, and wherein there is also a secondary coil surrounding the stem of the second pole and spaced inwardly from the face of said pole.

9. A liywheel magneto as set forth in claim 7, including means enabling the breaker mechanism to be adjusted so that the separation of the breaker points during each rotation of the fiywheel and magnets may take place substantially simultaneously with the establishing of the shunt magnetic circuits or substantially simultaneously with the completion of the establishment of the reverse magnetic circuit or at any intervening time.

10. In a flywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including circularly spaced first and second and third poles magnetically connected at their inner ends and having outer faces extending circularly to substantial extents which second pole includes a stem and has its face substantially equally spaced from the faces of the first and third poles, the core structure also including primary and secondary coils surrounding the stem of the second pole and spaced inwardly from the face of said pole; a flywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; first and second pairs of permanent magnets carried by the fiywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, the two magnets of one pair being charged in one direction and the two magnets of the other pair being charged in the opposite direction and the several magnets being so spaced and related that successively during each rotation: (a) both magnets of the first pair overlie the first pole face when both magnets of the second pair overlie the second pole face, (b) the trailing magnet of the first pair and the leading magnet of the second pair respectively partly overlie the first and third pole faces and the leading magnet of the first pair and the trailing magnet of the second pair simultaneously partly overlie the s econd pole face, (c) the leading magnets of the two pairs respectively overlie the second and third pole faces when the trailing magnets of the two pairs are respectively in positions substantially opposite the spaces between the first and second pole faces and between thc second and third faces, (d) both magnets of the first pair overlie the second pole face when both magnets of the second pair overlie the third pole face; and a breaker mechanism including separable points in series with the primary coil and including means for causing the repetitive separation of the points in timed relationship with the rotation of the flywheel and magnets.

1l. A flywheel magneto as set forth in claim 10, including means enabling the breaker mechanism to be adjusted so that the separation of the breaker points during each rotation of the ywheel and magnets may take place substantially immediately before the magnets reach position (b) or immediately before the magnets reach position (d) or at any intervening time.

12. A flywheel magneto as set forth in claim 10, wherein the ywheel has an annular flange formed of magnetic material and surrounding the core structure and having a cylindrical inner face; wherein there is provided a circularly extending magnetic connecting device engaging at its outer face with the inner face of 10 the flywheel flange and having a cylindrical inner face; and wherein the magnets of the two pairs engage at their outer faces with said inner face of the connecting device.

13. In a ywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including first and second separate pole pieces having at least two circularly spaced poles magnetically connected at their inner ends and having outer faces in a cylindrical surface concentric with the axis of the shaft, said first of which pole pieces is transversely notched to provide two substantially parallel faces and two beveled faces and said second of which pole pieces is shaped to provide faces engaging and fitting said faces of the notched portion of the first pole piece, one of the said poles including a generally radial stem and circularly extending opposite projections at the outel` end of the stem, the core structure also including primary and secondary coils surrounding said stem of last said pole and located inwardly from said projections thereon; a flywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; and a plurality of permanent magnets carried by the flywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, said mag nets serving to establish and interrupt magnetic circuits through the poles and through the coils.

14. In a flywheel magneto, the combination of a rotatable shaft; a stationary core structure adjacent the shaft including first pole piece having two opposite pole faces in a cylindrical surface concentric with the axis of the shaft and including a second pole piece separate from the first pole piece and comprising a stem and circularly extending opposite projections with a pole face thereon also in said cylindrical surface, said first pole piece having a notch about midway between the pole faces thereof which has beveled faces and the stem of said second pole piece being entered in said notch in the first pole piece and having faces positioned to engage and fit said beveled faces of the notch, a primary coil surrounding said stem and located inwardly from said projections thereon; a flywheel secured to the shaft adjacent the core structure and including a circularly extending magnetic connecting means; and a plurality of permanent magnets carried by the flywheel and having outer faces magnetically connected with said connecting means and having inner faces so located that they move in a common path and in close proximity to the pole faces, said magnets serving to establish and interrupt magnetic circuits through the poles and through the coil.

References Cited in the file of this patent UNITED STATES PATENTS 1,620,060 Billon Mar. 8, 1927 2,582,866 Harsch Ian. l5, 1952 FOREIGN PATENTS 253,484 Gr'eat Britain Feb. 24, 1927 947,659 France Jan. 17, 1949 

